1. Field of the Invention
The present invention relates to the analysis and measuring out of the constituents of solid or liquid media, notably constituents of biological media.
In present day practice, analyses and measuring out is carried out by manipulating equipment, sampling devices and reactants, which are mostly exposed to the ambient atmosphere.
Automatized devices aimed at reducing the number of manual operations to be effected for each measurement are also known.
2. Description of the Prior Art
Thus, in particular, the ACA system marketed under this name by the du Pont Company, Instrument Products Division, Wilmington, Delaware, USA, comprises a container of plastics material, containing test reactants and which has to serve as a measuring cup; however this container must be introduced, behind the separate container containing the specimen to be tested, in a very complex installation, necessary in order that strict operational conditions may be respected, enabling the production of reliable results. This system operates by photometry and necessitates the placing in position of an accurate optical cell outside the reaction container, including the effects of the two transparent walls of the latter, resulting in a complex system and in certain limitations in the variety of the possible tests.
Another system, marketed under the name Clinicard by Instrumentation Laboratory (represented by R. Delhomme and Cie, 30 boulevard Saint-Jacques, Paris), comprises a pocket enclosing a cup for single use with three compartments, formed entirely of molded plastics material transparent to the ultraviolet. In such a device, the parts which must enable the measurement have to be masked until the last moment to avoid subjecting them to finger marks or to scratches, since it is necessary, prior to any measurement, to take the three compartment cup and to introduce into one of the compartments the pre-established amount of reactants. In addition, the latter can only be in solid form. Besides, the filling of the measuring cup by means of the solid reactant, a diluant (obligatory) and the specimen, in their three respective compartments, necessitate the piercing of the diaphragms closing the orifices formed on the upper surface of said cup, and this by means of a triple perforator. The orifices thus opened must then be replugged. This system is not capable of automatization.
An apparatus is also known for unit analyses on micro-amounts, marketed under the name STAC by Technicon, comprising an analytical cell constituted by two tanks and containing reactants in lyophilized form. The method of putting these cells into operation is very sophisticated and the preservation of the lyophilized reactants requires a minimum of precautions. In addition, this presentation of the reactants necessitates their dilution before any measurement, which can be a considerable drawback where the need to carry out an analysis with an utmost urgency is involved.
Whatever the devices or apparatuses available today, consequently, it has not been possible to carry out analyses and measurements simply and practically, without applying sophisticated equipment, and especially without having need for operating with extreme care and following strict operational techniques.